Fuel injector control mechanism



P 1945- M. E. CHANDLER 2,384,282

FUEL INJECTOR CONTROL MECHANISM Filed July 22, 1942 l4 8 /3 I 24 v y as6 9 26 Q 88 u I 2 7 V /8 J 98 V I I so I f 2 so v I 27 i -86 v Q f 8;Fuel 1 z gp %1\ 11 1/ 19 I as 35 's 44 1 3 4 5 J /2 3, 3 5/ 40 57 6 5a 13g mvtrwon Ml H011 Efihan dler BY A WATTORY av.

- ll, suitably connected Patented Sept. 4, 1945 2,384,282 FUEL msscroacomer. MECHANISM Milton E. Chandler, New Britain, Conn., assignor toChandler-Evans Corporation, a corporation I i ofDelaware ApplicationJuly 22, 1942, Serial No. 451,873 I 8 Claims. (01. 123-140) My inventionrelates mechanism.

It has among its objects to provide an improved control mechanismadapted to use in internal combustion engines equipped with fuelinjectors, and, more particularly, to control such engines used onairplanes or the like. A further object of my invention is to providesuch an improved controlling mechanism wherein the quantity of fueldelivered through the injectors to the engine is so controlled as tovary as a function of air flow. A further object of my invention is toprovide improved injector controlling servomechanism controlled asaforesaid and controlling the by-passing of fuel around the fuelinjector pump to vary the quantity Of fuel delivered to the injectors.Other objects of my invention are to provide such an improved systemespecially adapted to use in connection with supercharged engines andwherein the operation of a servomechanism is automatically controlled inan improved manner in accordance with variations in the operation of theengine. These and other objects and advantages of my improvements will,however, hereinafter more fully appear.

In the accompanying drawing, I have shown for purposes of illustrationtwo embodiments which my invention may assume in practice.

In this drawing,

Figure 1 is a diagrammatic view of a supercharged airplane engineequipped with my improvements, the same being shown, for simplicity ofillustration. applied to a single cylinder of the engine, and .i

Fig. 2 is a similar diagrammatic view of a modified form of theservo-mechanism.

In the illustrative embodiment in Figure 1, I have shown an airplaneengine, generally indicated at I. including a plurality of cylinders,one of which is shown for illustrative purposes at 2 having a piston 3movable therein, with fuel being supplied to the cylinder through aninjector nozzle 4 and air through a connection 5 from a manifold 6connected to a supercharger l which, in turn, receives its air supplyfrom a scoop 8 through an air venturi 9, while my improved controllingmechanism controls the fuel supply to the injector nozzle 4 inaccordance with variations in air flow as hereinafter described. v

The fuel is supplied to the injector 4 from a tanl: III by a constantpressure fuel transfer pump to said tank through an inlet pipe [2, Whilethe pump II delivers through a discharge pipe l3 and a check valve l4into a to fuel injector control a diaphragm" in a closed casing 3 lventuri 35 and leads chamber I 5 which communicates through a checkvalve IS with a pipe l'l delivering to the injector As shown, aninjector pump l8 acts upon the fuel in the chamber ii to deliver thesame to the indector at the desired pressure through the check valve I6,this pump i8 being operated by a suitable eccentric It on theengine I.Further, a by-pass 20 isprovided between the chamber l5 and the inlet ofthe pump H, and the flow throughthis by-pass 20 is'automatically variedas hereinafter described by an injector controlling valve 2l, herein aneedle valve longitudinally adjustable relative to a tapered seat 22 inthe wall of casing 23 enclosing the chamber l5 and opposite check valvell.

Cooperating with this injector control valve 2| is improved controllingmechanism therefor controlled by the air flow through the air scoop land air venturi I to the supercharger I. Herein, this mechanism includesa pipe 24 connected to the scoop I and a pipe 25 connected to the throatof the air venturi 9. As shown, a valve 26 controlled by an aneroid 21is also connected in a by-pass 2! connecting the pipes 24 and 25 in suchmanner as to compensate for variations in altitude. The pipe 24connected to the scoop is also connected by a pipe 29 leading to oneside of while a pipe 32 leads from the pipe 25 and the venturi throat,to the opposite side of the diaphragm 30 in the casing 3|. As shown, avalve stem 33. is connected to the diaphragm 30 and a coil sprin 33normally biases this diaphragm and valve stem to the right. Thus, itwill be apparent that as the airflow to the supercharger 1 and enginemanifold 6 varies, the pressures in the throat of the venturi 9 andscoop 8 will be transmitted to opposite sides of the spring loadeddiaphragm 30 in such manner as to adjust the valve stem 33 in accordancewith variations in the differential of throat and scoop pressures.

Operatively associated with the mechanism including the air controlleddiaphragm 30 is also fuel pressure controlled diaphragm mechanism. Asshown, a venturi 35 is provided in the fuel inlet pipe l2 .--leading tothe fuel pump H, and a pip 36 leads from the one side of a fuel pressurecontrolled diaphragm 31 in a closed casing 38, corresponding to thecasing 3!, while a pipe 39 is also connected to the fuel inlet pipe l2on the inlet side of the to the opposite side of the diaphragm 31.

Operatively connected to the valve stem 33 is an improved cooperatingservo-mechanism, generthroat of this venturi to bers 43 and 48,respectively, to a common return side of the pump 48.

passage 88 to the intake having pipes 8|a, 82a

Outlet ports 8| and 82 leading therefrom are also controlled by thespools 4| and 42, and one of these pipes lilo communicates with acylinder 88 on one side of a piston 84 carrying the injector controllingvalve 2|, while the other pipe 82a delivers to said cylinder on theopposite side of the piston 84.

Thus, as the valve stem 88 is adjusted to the left upon an increase inair flow through the air venturi 8, the spools 4|, 42 will be moved tothe left relative to the ports 8|, 82 in the servomechanism 48, and oilwill be supplied from the pump 48 through the inlet 41 and the port 8|to the pipe 5|a to move the piston 84 to the left and thereby tend toclose the injector control valve 2|, while the oil on the opposite sideof the piston 84 will be free to return through the pipe 82a to port 82and chamber 48, and, through the causes a reduction in the pressuredifferential on the opposite sides of diaphragm 88, and a consequentmovement of the spools 4| and 42 to the right, thereby connecting theoutlet of oil pump 48 thru inlet 41, chamber 44, port 82 and pipe 82a tocylinder 83 at the left of piston 84. At the same time, the cylinder atthe right of piston 84 is vented thru pipe ila, port 8|, chamber 43, andpassages 48 and 88 to the inlet side of pump 48. The piston 54 thereforemoves to the right, opening the by-pass valve 2|, and decreasing thequantity of fuel flowing to the engine.

It will, accordingly, be evident that the injector control valve 2| willbe moved to the-left, i. e., to reduce the amount of fuel dischargedfrom the chamber l8 through the by-pass 28, and returned to the inletside of the fuel pump II and thereby increase the flow to the injector4, whenpassages 48 and 58, to the inlet side of the pump On the otherhand, a decrease in theair ever the air flow to the engine increases insuch manner as to cause the air diaphragm 88 to be moved to the left.Similarly, when the air flow decreases, the valve 2| will be opened toincrease,

the fuel flow through the by-pass 28 and accordingly increase the amountof by-passed fuel and reduce the fuel supply to the injector 4.

Whenever the piston 84 starts to move the valve 2| in either direction,the motion continues until the valve stem 88 is restored toits normalposition wherein does not occur until the fuel flow is changed by anamount such that the new fuel differential pressure acting on diaphragm81 balances the new air differential pressure acting on diaphragm 38.

Cooperating with the above described servomeehanism further to controlthe position of the spools 4| and 42 is mechanism controlled by thepressure in the manifold 6. As shown, an extension is provided on theright hand end of the valve stem 38 and extends into an end aneroidchamber 55a, while a coiled spring 58 acts beports 8| and 82 are closed.This lever 58 and has its opposite end fixed to the casing 82, while acoiled spring 88 inside the aneroid normally expands the latter. Asshown, a pipe 84 connects the chamber a with the manifold. Thus, as theair flow to the engine increases and the pressure increases in themanifold 8, whenever the bellows 8| collapses sumciently to overcome thespring 88, the upper end of lever 58 will be swung to the left to imparta further movement of the stem 88 to the left and thereby enrich themixture; while upon a decrease in pressure in the manifold, the aneroidexpands, thereby causing a'movement of stem 88 to the right, in a fuelflow decreasing direction. When the bellows 8| expands far enough sothat the upper end of lever 88 is stopped by the casing 82, the valvestem 88 is then placed wholly under the control of diaphragms 28 and 81.

In the operation of the complete device, the variations in air flow tothe supercharger 'I will cause adjustment of the air diaphragm 88 as afunction of the differential of throat and scoop pressures in the airventuri 8, while the fuel diaphragm 81 will act to balance the airdiaphragm 88 due to its connection to the throat and scoop of the fuelventuri 88. With the spools 4| and 42 movable with the valve stem 88,oil flow from the inlet 41 will be controlled by the diaphragms 88 and81 and spools 4|, 42, in such manner as to adjust the injector controlvalve 2| to open or close the by-pass 28, and, as a result, decrease orincrease the quantity of fuel delivered by the injector pump i8 throughthe pipe l1 to the injector nozzle 4. Thus, the fuel supplied by theinjector nozzle 4 to the cylinder 2 will be varied as a function of thequantity of air being delivered to the cylinder throughout the normaloperation of the engine. When, however, the pressure in the manifold 8increases, as, for example, during overload, the pressure therein willbe transmitted through pipe 84 to aneroid 8|, and a further movement ofthe spools 4|, 42 in the same direction will be effected as a result ofthe increase in air flow, in such manner as thereby further to enrichthe mixture automatically as a function of the in, crease in pressure inthe manifold.

A throttle 88 is located in the air induction system downstream from theventuri 8. The throttle 88 rotates on a shaft which also carries an arm82, manually operable by means of a suitable handle 88. Arm 82 ispivotally attached to a link 84 whose opposite end is pivoted on an arm88. The arm 88 is pivotally mounted on a fixed support 88. The arm 88carries near its upper end a pin 88.

A rod 82 is attached to the piston 84 and extends to the outside ofcylinder 88. The outer end of rod 82 is pivotally connected to a link84, which is pivoted at an intermediate point on an arm 88 whoseopposite end is attached to the fixed support 88. The lower-end of link84 carries a cam 88 which cooperates with the pin 88.

When the parts are in the positions shown in the drawing, the throttleis somewhat more than half open, and the pin 88 has been moved to aposition where it is not in the path of motion of cam 88. As thethrottle is moved toward closed position, the arms82 and 88 are movedcounterclockwise, carrying the pin 88 to the right. As

the motion of'pin 88 to the right continues, a

position is reached where it engages cam and forces the link 64 torotate in a counterclockwise direction, thereby moving the piston 54 andvalve 2| to the left, or in a valve closing direction. This closingmovement of valve 2| causes an increased discharge of fuel to the engineby the pump I6 and hence results in an enrichment of the mixture of fueland air supplied to the engine.

This throttle controlidle mechanism is provided to insure that themixture will be sufficiently rich during idling to enable the engine torun smoothly. I

In Fig. 2, I have shown a modified construction of servo-mechanism. Thismechanism generally corresponds to that heretofore described, save thata reversible electric motor 66 is provided connected through any usualtelescopic threaded connection 61 with an injector control valve 66corresponding to the valve 2|, while a reversing switch 69 has}; controllever HI disposed between spaced spools H on a valve stem 12 to thevalve stem 33. The remainder of the mechanism being that heretoforedescribed, it will be evident that this mechanism will functionessentially similarly, with the reversing switch 69 operated as thevalve stem 12 is moved reversely, and this switch 69 acting to reversethe motor 66 in such manner as thereby, through the threaded connection61, to reversely operate the injector controlling valve 68 in the samesequence as heretofore.

It will be understood that in the use of my improved construction forairplane engines, I contemplate the provision of the usual ignitionmechanism (not shown) in the cylinder. It will be evident, however, thatif desired, the above described control mechanism may be used withoutsuch ignition mechanism in a usual Diesel installation.

While I have in this application described certain fornis which myinvention may assume in practice, it will be understood that the sameare shown forpurposes of illustration, and that the invention may bemodified and embodied in v various other forms without departing fromits spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a fuel injector control mechanism, an air conduit, controllingmeans responsive to variations in the quantity of air flowing throughsaid conduit, hydraulic control mechanism controlled by said controllingmeans, fuel injector mechanism including an injector pump having a valvefor varying the delivery of,said pump, means controlled by saidhydrauliccontrol mechanism for adjusting said valve to vary the deliveryof said pump as a function of air flow, a throttle controlling the airflow through said conduit, and means controlled by said throttle forautomatically varying the delivery of said pump during idling.

2. In a fuel injector control mechanism, an air conduit, controllingmeans responsive to variations in air fiow through said conduit, fuelinjector mechanism including an injector pump having a valve for varyingthe delivery of said pump, a reversible motor for reversely operatingsaid valve, and means including a reversing switch for said motorreversely operated by said controlling means as the air flow throughsaid conduit increases or decreases for operating said motor andactuating said valve to vary the delivery of said pump as a function ofair flow.

3. In a fuel supply system for an internal comcorresponding bustionengine, a first conduit for supplying combustion air to said engine,means for creating a first differential pressure indicative of thequantity of air fiowing thru said conduit, a second conduit forsupplying fuel to said engine, means ,;said motor means, means forcontrolling the supply of energy to said motor means including a memberhaving a normaljijposition in which said motor means is stationary andeffective upon movement from said normal position in opposite directionsto cause operation of said motor means in opposite directions, firstflexible diaphragm means responsive to said first pressure differential,second flexible diaphragm means responsive to said second pressuredifferential, and means connecting both said diaphragm means to saidmember so as to cause movement of said member when" the forces acting onsaid diaphragm means are unbalanced, said member being effectivewhenmoved from said normal position to cause operation of said motormeans in the proper direction to vary said one differential pressureuntil said diaphragms and member are returned to said normal positiomsothat said diaphragms remain in said normal position when thedifferential pressures are balanced, regardless of the position of saidcontrol means, and means responsive to the pressure in the intakemanifold of said engine and effective when said intake manifold pressureexceeds a predetermined value to apply to said member a force opposed tothat applied by said second diaphragm means so as to cause operation ofsaid motor means in a direction to increase the ratio of fuel-to-airsupplied to said engine.

4. In a fuel injection system for an internal combustion engine, a firstconduit for supplying combustion air to said engine, means associatedwith said conduit for producing two unequal pressures whose differenceis a measure of the rate of flow of air thru said conduit, a throttlefor controlling the fiow of air thru said conduit, injector pump meansfor delivering fuel at high pressure to the combustion chambers of saidengine, a second conduit for conveying fuel to said injector pump means,a metering restriction in said second conduit for producing adifferential pressure indicative of the quantity of fuel flowingtherethru, means responsive to the difference between said airdiiferential pressure and said fuel differential pressure forcontrolling the delivery of said injector pump means, and meanscontrolled by said throttle for varying the delivery of said pump meansduring idling.

5. In a fuel supply system for an internal combustion engine, a firstconduit for supplying com- 1 bustion air to said engine, means forcreating a first differential pressure indicative of the quantity of airflowing thru said conduit, a second conduit for supplying fuel to saidengine, means for creating a second differential pressure indicative ofthe quantity of fuel flowing thru said ,second conduit, means forcontrolling the flow thru one of said conduits and thereby one of saiddifferential pressures, electrical motor means for operating said flowcontrolling means, a source of electrical energy for said motor means,means for controlling the supply of electrical energy to said motormeans including a switch having a normal position in which said motormeans 4 is stationary and eifective upon movement from said normalposition in opposite directions to close electrical circuits which causeoperation of said motor means in opposite directions, first flexiblediaphragm means responsive to said first pressure diiferential. secondflexible diaphragm means responsive to said second pressuredifferential, and means connecting both said diaphragm means to saidswitch so as to cause'movement of said switch when the forces acting onsaid diaphragm means are unbalanced, said switch being effective whenmoved from said normal position to cause operation of said motor meansin the proper direction to vary said one differential pressure untilsaid diaphragms and member are returned to said normal position, so thatsaid diaphragms remain in said normal position when the differentialpressures are balanced, regardless of the position of said controlmeans, and means responsive to the pressure in the intake manifold ofsaid engine and effective when said intake manifold pressure exceeds apredetermined value to apply to said switch a force opposed to thatapplied by said second diaphragm means so as to cause operation of saidmotor means in a direction to increase the ratio of fuelto-air suppliedto said engine.

6. In a fuel supply system for an internal combustion engine, a firstconduit for supplying combustion air to said engine, means for creatinga first differential pressure indicative of the quantity of air flowingthru said conduit, a second conduit for supplying fuel to said engine,means for creating a second diilerentiai pressure indicative of thequantity of fuel flowing thru said second conduit, means for controllingthe flow diaphragm means so as to cause operation of said thru one ofsaid conduits and thereby one of said differential pressures, hydraulicmotor means for operating said fiow controlling means, a source of fluidunder pressure for supplying energy to said motor means, means forcontrolling the supply of fluid to said motor means including a valvehaving a normal position in which said motor means is stationary andeifective upon movement from said normal position in opposite directionsto cause operation of said motor means in opposite directions, firstflexible diaphragm means responsive to said first pressure differential,second flexible diaphragm means responsive to said second pressuredifferential, and means connecting both said diaphragm means to saidvalve so as to cause movement of said valve when the forces acting onsaid diaphragm means are unbalanced, said valve being effective whenmoved motor means in a direction to increase the ratio of fuel-to-airsupplied to said engine.

'7. In a fuel supply system for an internal combustion engine, a firstconduit for supplying combustion air to said engine, means for creatinga first diiferential pressure indicative of the quantity of air flowingthru said conduit, a second conduit for supplying fuel to said engine,means for creating a second differential pressure indicative of thequantity of fuel flowing thru said second conduit, means for controllingthe flow thru one of said conduits and thereby one of said differentialpressures. first diaphragm means responsive to said first pressuredifferential, second diaphragm means responsive to said second pressuredifferential, means connecting both said diaphragm means to said flowcontrolling means, said diaphragm means being effective to operate saidflow controlling means to maintain a substantially constant fuel-to-airratio, and means responsive to the pressure in the intake manifold ofsaid engine and effective when said intake manifold pressure exceeds apredetermined value to apply to said valve a force opposed to thatapplied by said second diaphragm means so as to cause operation of saidmotor means in a direction to increase the ratio of fuel-to-air suppliedto said engine.

8. In a fuel supply system for an internal combustion engine, incombination, means for conveying air to said engine for combustionpurposes, an injector pump for delivering fuel to said engine, a fuelpump for supplying the inlet of said injector pump with fuel undersuperatmospheric pressure, means for controlling the quantity of fueldelivered to said engine by said injector pump, electrical motor meansfor driving said delivery controlling means, and means responsive to thequantity of air supplied to said engine for controlling said electricalmotor means.

MILTON E. CHANDLER.

